> On Sat, Feb 23, 2008 at 10:11 AM, Andrew Morton> <akpm@linux-foundation.org> wrote:> > Seems a poor idea to me. Sure, oprofile is "hard to set up", but not if> > your distributor already did it for you.> > Have you tried sysprof? It's really nice to setup and use compared to > oprofile when profiling user-space.

yes, it's very nice and very usable - and that's all that matters really. It's almost a _duty_ of the mainstream kernel to include that trivial 200 lines of sysprof code, given how poor instrumentation support is on Linux.

As a comparison, here's a session of a newbie developer, meeting oprofile for the first time in his life (using a fresh package, oprofile-0.9.3-6.fc8):

----------------------> [ Newbie: WTF, no GUI tool? ] [ Narrator: we lose 90% of the developers at this point. ] [ Newbie is adventurous and has heard about opcontrol and tries it. ]

# opcontrol -s No vmlinux file specified. You must specify the correct vmlinux file, e.g. opcontrol --vmlinux=/path/to/vmlinux If you do not have a vmlinux file, use opcontrol --no-vmlinux Enter opcontrol --help for full options

[ Newbie: WTF? Doesnt oprofile think that what I want to do is to profile ... the currently running kernel, wherever a kernel is and whatever a vmlinux might be?? ]

[ Narrator: At this point oprofile has confused about 99% of all user-space developers who have no freaking idea about what a vmlinux is. ]

[ Newbie user figures that --no-vmlinux might be the right option: ]

# opcontrol -s --no-vmlinux Option "--setup" not valid with "-s".

[ Newbie: WTF? what not valid? Why should i care? Damnit, i only want to profile stuff!!! ]

[ The newbie user eventually finds out that opcontrol help text is buggy and that -s does not mean --start, but --setup. ]

[ Narrator: we've now lost 99.99999% of the testers at this point. The reamining 10 kernel developers still using oprofile have written up all the commands to the back of their keyboards, for easy reference. ] <----------------------

We should hang our collective heads in shame. Oprofile is an utter joke in terms of usability. It had 5-10 years to get its stuff together and didnt.

200 lines of totally isolated sysprof code is the least thing we can do which we _must do_ to help our users.